Used one years ago on my 90/6. Sound was louder/deeper but not offensive. It did not have removeable baffels. Adjustment for mixture was very small if at all with stock jets. Certainly within stock range of adjustment. MPG was unchanged, still excellent. No seat of the pants difference in power.

My R90 needs an exhaust and I was wondering how the Mac 2 into 1 system sounds. With and with out baffels. How did they fit? And did you need to jet the carbs different?

Had a set on my old R90/6. Sounds great with baffles - not too loud (loud pipes save lives). Never ran it with baffles removed. Good fit, easy to install and remove. No need to re-jet (Bings) although with your bike at your elevation it might be an option. I think I still have the Mac's out in the barn - might be a bit beat up. Let me know if you want 'em.

Goood to know guys, I am mid restore of mine and I was thinking they may be a nice addition to the restore while still saving some money over new. I do not want it to be too loud but I do enjoy the sound of a nice motor.

CrayDDS,
How beat up are yours? I amy be interested in them if I can make them look good.

Man. 5 to 7 hp on most of these bikes is around a 10 to 15% reduction in peak power. Very noticeable yet the people with experience with the pipes on this thread didn't notice it? Of course, they didn't notice any such gains in lower rpms either. Typically, two into ones just like crossovers cost a bit of power on top for a bit more power somewhere else. In my experience with Luftmeister two into ones, the trade off isn't nearly so grand. From the looks of all the airhead race bikes I see running two into ones, a lot of people like the tradeoff as far as getting around tracks the fastest is concerned. Of course, some opt for more top end. It all depends on your priorities.

[QUOTE=supershaft;18191583]Man. 5 to 7 hp on most of these bikes is around a 10 to 15% reduction in peak power. Very noticeable yet the people with experience with the pipes on this thread didn't notice it? Of course, they didn't notice any such gains in lower rpms either. Typically, two into ones just like crossovers cost a bit of power on top for a bit more power somewhere else. In my experience with Luftmeister two into ones, the trade off isn't nearly so grand. From the looks of all the airhead race bikes I see running two into ones, a lot of people like the tradeoff as far as getting around tracks the fastest is concerned. Of course, some opt for more top end. It all depends on your priorities.[/QUOTE

Got my exhaust today and I am not very happy with the first fit. One side will rub the center stand and the rear brake lever also hits the side. My brake lever is somewhat tweaked from the PO dropping it so maybe that will help. Wish now I would have spent the extra money and went with stock